1. Field of the Invention
The present invention relates to a number lock device and, more particularly, to an idiot-proof lock device.
2. Description of the Related Art
A conventional lock device “B” in accordance with the prior art shown in FIGS. 8-11 comprises a locking unit 4, a connecting unit 5, and a latch 6. The locking unit 4 includes a shank 41, a rotation knob 42, a control wheel 43, a plurality of number wheels 44, a plurality of locating pieces 45, a plurality of snap-fit members 46, and a plurality of locking elements 47. The shank 41 has a first end provided with a flange 411. The shank 41 has an interior provided with a through hole 413. The shank 41 has a periphery provided with a slot 412 connected to the through hole 413. The shank 41 has a second end provided with a first locking hole 415. The shank 41 has an outer surface provided with a plurality of bosses 414 which are arranged between the flange 411 and the first locking hole 415. The bosses 414 of the shank 41 are spaced from each other and are arranged in a linear manner. The rotation knob 42 is mounted on the shank 41 and has a first end provided with a receiving chamber 421 and a second end provided with a mounting bore 422 mounted on the flange 411 of the shank 41. The control wheel 43 is received in the receiving chamber 421 of the rotation knob 42. The control wheel 43 has an interior provided with a first mounting hole 431 mounted on the shank 41. The first mounting hole 431 of the control wheel 43 has a surface provided with two first recesses 4312 and a rail 4311. The two first recesses 4312 of the control wheel 43 are perpendicular to each other. Each of the number wheels 44 is mounted on the shank 41, and one of the number wheels 44 abuts the rotation knob 42. Each of the number wheels 44 has an interior provided with a receiving hole 441. The receiving hole 441 of each of the number wheels 44 has a first end provided with a plurality of locking grooves 4411 and a second end provided with a plurality of ribs 4412. The ribs 4412 of each of the number wheels 44 are spaced from each other and are arranged in an annular manner. Each of the locating pieces 45 is received in the receiving hole 441 of a respective one of the number wheels 44. Each of the locating pieces 45 has an end portion provided with an engaging face 452 engaging the ribs 4412 of the respective number wheel 44. Each of the locating pieces 45 has an interior provided with a second mounting hole 451 mounted on the shank 41. The second mounting hole 451 of each of the locating pieces 45 has a surface provided with two second recesses 4511. The two second recesses 4511 of each of the locating pieces 45 are perpendicular to each other. Each of the snap-fit members 46 is received in the receiving hole 441 of a respective one of the number wheels 44 and abuts a respective one of the locating pieces 45. Each of the snap-fit members 46 has an interior provided with a third mounting hole 461 mounted on the shank 41. The third mounting hole 461 of each of the snap-fit members 46 has a surface provided with two third recesses 4612 and a lug 4611. The two third recesses 4612 of each of the snap-fit members 46 are perpendicular to each other. Each of the snap-fit members 46 has a periphery provided with a retaining groove 462. Each of the locking elements 47 is mounted on the retaining groove 462 of a respective one of the snap-fit members 46 and engages the locking grooves 4411 of a respective one of the number wheels 44.
The connecting unit 5 includes a connector 50 connected with the shank 41 of the locking unit 4 by a pin 521 and an elastic member 511 mounted on the shank 41 of the locking unit 4 and biased between one of the snap-fit members 46 of the locking unit 4. The connector 50 of the connecting unit 5 has a side provided with a recessed mounting portion 51 for mounting the elastic member 511 and for connecting the shank 41 of the locking unit 4. The connector 50 of the connecting unit 5 has a periphery provided with a second locking hole 52 which is aligned and concentric with the first locking hole 415 of the shank 41. The pin 521 of the connecting unit 5 is extended through the second locking hole 52 of the connector 50 and is inserted into the first locking hole 415 of the shank 41 to connect the connector 50 of the connecting unit 5 with the shank 41 of the locking unit 4.
The latch 6 has a first end provided with a shaft 62 inserted into the through hole 413 of the shank 41 and a second end provided with an enlarged head 61 protruded outward from the through hole 413 of the shank 41. The shaft 62 of the latch 6 has a periphery provided with a plurality of protrusions 63 slidably mounted in the slot 412 of the shank 41. The protrusions 63 of the latch 6 are spaced from each other and are arranged in a linear manner. The protrusions 63 of the latch 6 are in turn extended through one of the two first recesses 4312 of the control wheel 43, one of the two second recesses 4511 of each of the locating pieces 45 and one of the two third recesses 4612 of each of the snap-fit members 46, and the bosses 414 of the shank 41 are in turn extended through the other one of the two first recesses 4312 of the control wheel 43, the other one of the two second recesses 4511 of each of the locating pieces 45 and the other one of the two third recesses 4612 of each of the snap-fit members 46.
In operation, when the number wheels 44 are rotated to construct the correct code, the latch 6 is unlocked and released from the locking unit 4 so that the latch 6 is disposed at an opened state and can be removed from the shank 41 of the locking unit 4. In adjustment, the rotation knob 42 is rotated through a quarter (¼) circle. Then, the number wheels 44 are rotated to change the code. Then, the rotation knob 42 is rotated through a quarter (¼) circle in the opposite direction. Thus, adjustment of the code is accomplished.
However, the rotation knob 42 can be rotated easily and freely so that the code will be changed when the rotation knob 42 is rotated by the user unintentionally, thereby causing inconvenience to the user. In addition, the user has to initially position each of the locking elements 47 on the retaining groove 462 of the respective snap-fit member 46 and then insert each of the locking elements 47 and the respective snap-fit member 46 into the respective number wheel 44 so that the locking unit 4 is not assembled easily and quickly, thereby greatly wasting the time and energy of assembly.